All things related to multicast

[Marshall Eubanks <>]

Dear Harvard;

1.) We are also involved with multicast monitoring and would be
glad to work with you in resolving problems. We can mtrace
to your through Sprint, etc.

2.) My multicast contact at Sprint is Jeff Loughridge 
<>;
 
but queries should also be sent 
,
 a mailbox for
questions or issues about multicast on Sprint's network.

3.) I would separate the operators of the beacon (who may or may not
have anything to do with the network the beacon is operating on) from the 
network & NOC engineers (who do). In other words, I do NOT think that
a e-mail address for a beacon site should be required or trusted.

4.) See http://beaconserver.accessgrid.org:9999/host for IP addresses.
I use MBGP to see how the multicast connectivity should go.

5.) I think that most connectivity troubles are due to MSDP back-holes.
By comparison, MBGP appears pretty stable. I have been working on
the inverse problem (taking msdp logs from several sites, and finding
out where the blackholes are), and am convinced that this can be done
given sufficient numbers of logs.

6.) I do not see a beacon from nordu.net, so I cannot see whether
we have connectivity with you or not.


                                   Regards
                                   Marshall Eubanks


   Multicast Technologies, Inc.
   10301 Democracy Lane, Suite 410
   Fairfax, Virginia 22030
   Phone : 703-293-9624          Fax     : 703-293-9609     
   e-mail : 

     http://www.on-the-i.com         

 Test your network for multicast : http://www.multicasttech.com/mt/
Check the status of multicast in real time : 
http://www.multicasttech.com/status/index.html


"Kevin C. Almeroth" wrote:
> 
> >>To: 
> >>
> >>Subject: Beacons, in-addr.arpa and forward-DNS
> >>From: Havard Eidnes 
> >><>
> >>Hi,
> >>
> >>I started looking a bit closer at the accessgrid beacon multicast
> >>reachability status, with a view towards finding out what is causing
> >>some of the reachability problems my beacon is experiencing.
> >>
> >>I noticed that the accessgrid beacon status page now hsa 5 beacons
> >>which apparently do not have an in-addr.arpa DNS registration, which
> >>looks a little lame.
> >>
> >>Furthermore, I found at least two beacons that I have connectivity
> >>problems with (nephilim.sprintlink.net and vogt.sprintlink.net)
> >>where there does not exist a name-to-IP-address mapping for these
> >>names.  Needless to say, this creates somewhat of a problem when it
> >>comes to debugging the connectivity problems from my end of things.
> >>
> >>Furthermore, it appears that the user/host combinations are similar
> >>to e-mail addresses -- I assumed that is the intent.  I'll however
> >>bet that attempts at sending e-mail to the beacon identifiers would
> >>generate quite a number of bounces, something which again makes
> >>debugging more difficult than it otherwise can be.
> >>
> >>
> >>I'll therefore appeal to those of you who run beacons on the
> >>accessgrid group to at least make sure that reverse *and* forward
> >>mappings for the beacon IP addresses are consistent with reality,
> >>and that such mappings exist.
> >>
> >>I'm not sure about whether it should be possible to send e-mail to
> >>the beacon identifiers (for what it's worth, it is possible to send
> >>e-mail to my beacon identifier).
> >>
> >>Secondly, I would like to get in touch with the administrator of the
> >>sprintlink.net participant beacons, to get the IP addresses of the
> >>participating beacons, and so that we can (off-line) look into what
> >>is causing our connectivity problems; pointers or replies
> >>appreciated.
> >>
> >>Best regards,
> >>
> >>- Håvard
> >>
> >>
> >>

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